Institute des Hautes etudes Scientifiques

Chartres-de-Bretagne, France

Institute des Hautes etudes Scientifiques

Chartres-de-Bretagne, France
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Bini D.,CNR Institute for applied mathematics Mauro Picone | Damour T.,Institute des Hautes Etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

We complete the analytical determination, at the 4th post-Newtonian approximation, of the main radial potential describing the gravitational interaction of two bodies within the effective one-body formalism. The (nonlogarithmic) coefficient a5(ν) measuring this 4th post-Newtonian interaction potential is found to be linear in the symmetric mass ratio ν. Its ν-independent part a5(0) is obtained by an analytical gravitational self-force calculation that unambiguously resolves the formal infrared divergencies which currently impede its direct post-Newtonian calculation. Its ν-linear part a5(ν)-a5(0) is deduced from recent results of Jaranowski and Schäfer, and is found to be significantly negative. © 2013 American Physical Society.


Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes Etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We analytically compute, to linear order in the mass ratio, the "geodetic" spin-precession frequency of a small spinning body orbiting a large (nonspinning) body to the eight-and-a-half post-Newtonian order, thereby extending previous analytical knowledge which was limited to the third post-Newtonian level. These results are obtained applying analytical gravitational self-force theory to the first-derivative level generalization of Detweiler's gauge-invariant redshift variable. We compare our analytic results with strong-field numerical data recently obtained by Dolan et al. [Phys. Rev. D 89, 064011 (2014)]. Our new, high-post-Newtonian-order results capture the strong-field features exhibited by the numerical data. We argue that the spin precession will diverge as ≈-0.14/(1-3y) as the light ring is approached. We transcribe our kinematical spin-precession results into a corresponding improved analytic knowledge of one of the two (gauge-invariant) effective gyrogravitomagnetic ratios characterizing spin-orbit couplings within the effective-one-body formalism. We provide simple, accurate analytic fits both for spin precession and the effective gyrogravitomagnetic ratio. The latter fit predicts that the linear-in-mass-ratio correction to the gyrogravitomagnetic ratio changes sign before reaching the light ring. This strong-field prediction might be important for improving the analytic modeling of coalescing spinning binaries. © 2014 American Physical Society.


Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes Etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

Continuing our analytic computation of the first-order self-force contribution to Detweiler's redshift variable we provide the exact expressions of the ninth and ninth-and-a-half post-Newtonian terms. © 2015 American Physical Society.


Damour T.,Institute des Hautes Etudes Scientifiques
Classical and Quantum Gravity | Year: 2015

The 1974 discovery, by Russell A Hulse and Joseph H Taylor, of the first binary pulsar, PSR B1913+16, opened up new possibilities for the study of relativistic gravity. PSR B1913+16, as well as several other binary pulsars, provided direct observational proof that gravity propagates at the velocity of light and has a quadrupolar structure. Binary pulsars also provided accurate tests of the strong-field regime of relativistic gravity. General relativity has passed all of the binary pulsar tests with flying colors. The discovery of binary pulsars also had very important consequences for astrophysics, leading to accurate measurement of neutron star masses, improved understanding of the possible evolution scenarios for the co-evolution of binary stars, and proof of the existence of binary neutron stars emitting gravitational waves for hundreds of millions of years, before coalescing in catastrophic events radiating intense gravitational wave signals, and probably also leading to important emissions of electromagnetic radiation and neutrinos. This article reviews the history of the discovery of the first binary pulsar, and describes both its immediate impact and its longer-term effect on theoretical and experimental studies of relativistic gravity. © 2015 IOP Publishing Ltd.


Bini D.,CNR Institute of Neuroscience | Damour T.,Institute des Hautes Etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014

We extend the analytical determination of the main radial potential describing (within the effective one-body formalism) the gravitational interaction of two bodies beyond the fourth post-Newtonian approximation recently obtained by us. This extension is done to linear order in the mass ratio by applying analytical gravitational self-force theory (for a particle in circular orbit around a Schwarzschild black hole) to Detweiler's gauge-invariant redshift variable. By using the version of black hole perturbation theory developed by Mano, Suzuki and Takasugi, we have pushed the analytical determination of the (linear in mass ratio) radial potential to the sixth post-Newtonian order (passing through 5 and 5.5 post-Newtonian terms). In principle, our analytical method can be extended to arbitrarily high post-Newtonian orders. © 2014 American Physical Society.


Damour T.,Institute des Hautes Etudes Scientifiques
Classical and Quantum Gravity | Year: 2012

We review several theoretical aspects of the equivalence principle (EP). We emphasize the unsatisfactory fact that the EP maintains the absolute character of the coupling constants of physics, while general relativity and its generalizations (Kaluza-Klein, , string theory) suggest that all absolute structures should be replaced by dynamical entities. We discuss the EP-violation phenomenology of dilaton-like models, which is likely to be dominated by the linear superposition of two effects: a signal proportional to the nuclear Coulomb energy, related to the variation of the fine-structure constant, and a signal proportional to the surface nuclear binding energy, related to the variation of the light quark masses. We recall various theoretical arguments (including a recently proposed anthropic argument) suggesting that the EP be violated at a small, but not unmeasurably small level. This motivates the need for improved tests of the EP. These tests are probing new territories in physics that are related to deep, and mysterious, issues in fundamental physics. © 2012 IOP Publishing Ltd.


Nagar A.,Institute des Hautes Etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

Building on the recently computed next-to-next-to-leading order (NNLO) post-Newtonian spin-orbit Hamiltonian for spinning binaries we improve the effective-one-body description of the dynamics of two spinning black holes by including NNLO effects in the spin-orbit interaction. The calculation that is presented extends to NNLO the next-to-leading order spin-orbit Hamiltonian computed in. The present effective-one-body Hamiltonian reproduces the spin-orbit coupling through NNLO in the test-particle limit case. In addition, in the case of spins parallel or antiparallel to the orbital angular momentum, when circular orbits exist, we find that the inclusion of NNLO spin-orbit terms moderates the effect of the next-to-leading order spin-orbit coupling. © 2011 American Physical Society.


Damour T.,Institute des Hautes Etudes Scientifiques
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We discuss various ways in which the computation of conservative gravitational self-force (GSF) effects on a point mass moving in a Schwarzschild background can inform us about the basic building blocks of the effective one-body (EOB) Hamiltonian. We display the information which can be extracted from the recently published GSF calculation of the first-GSF-order shift of the orbital frequency of the last stable circular orbit, and we combine this information with the one recently obtained by comparing the EOB formalism to high-accuracy numerical relativity data on coalescing binary black holes. The information coming from GSF data helps to break the degeneracy (among some EOB parameters) which was left after using comparable-mass numerical relativity data to constrain the EOB formalism. We suggest various ways of obtaining more information from GSF computations: either by studying eccentric orbits, or by focusing on a special zero-binding zoom-whirl orbit. We show that logarithmic terms start entering the post-Newtonian expansions of various (EOB and GSF) functions at the fourth post-Newtonian level, and we analytically compute the first logarithm entering a certain, gauge-invariant "redshift" GSF function (defined along the sequence of circular orbits). © 2010 The American Physical Society.


Grant
Agency: European Commission | Branch: H2020 | Program: ERC-STG | Phase: ERC-StG-2015 | Award Amount: 1.50M | Year: 2016

Quantum Field Theory is a universal framework to address quantum physical systems with infinitely many interacting degrees of freedom, applicable both at the level of fundamental interactions, such as the subnuclear physics of quarks and gluons and at the phenomenological level such as the physics of quantum fluids and superconductivity. Traditionally, weakly interacting quantum field theory is formulated as a perturbative deformation of the linear theory of freely propagating quantum waves or particles with interactions described by Feynman diagrams. For strongly non-linear quantum field theories the method of Feynman diagrams is not adequate. The main goal of this proposal is to develop novel tools and techniques to address strongly non-linear quantum field theories. To achieve this goal we will search for hidden algebraic structures in quantum field theories that will lead to efficient algorithms to compute physical observables of interest. In particular we identify non-linear quantum field theories with exactly solvable sectors of physical observables. In this project we will focus on three objectives: - build general theory of localization in supersymmetric Yang-Mills theory for arbitrary geometrical backgrounds - find all realizations of symplectic and supersymplectic completely integrable systems in gauge theories - construct finite supersymmetric Yang-Mills theory in terms of the algebra of locally supersymmetric loop observables for maximally supersymmetric gauge theory The realization of the above objectives will uncover hidden quantum algebraic structures and consequently will bring ground-breaking results in our knowledge of quantum field theories and the fundamental interactions.


Grant
Agency: European Commission | Branch: H2020 | Program: MSCA-IF-EF-ST | Phase: MSCA-IF-2015-EF | Award Amount: 173.08K | Year: 2016

The proposed project concerns p-adic Hodge Theory, a major area of arithmetic algebraic geometry; it owes its existence to the 1968 observation of John Tate that the well-known Hodge decomposition of the singular cohomology of a complex manifold should have a p-adic analogue, in which the singular cohomology is replaced by the p-adic etale cohomology. There are currently two distinct approaches to the study of this Hodge-Tate decomposition. The first, developed mainly by Bloch, Kato, and Tsuji, uses algebraic K-theory, syntomic complexes, and p-adic vanishing cycles, while the second, more in line with Tates original ideas, was developed by Faltings using his almost mathematics and purity theorems. The project will resolve a number of outstanding open problems in the field, including the relation between these distinct methods, the resolution of a 1983 conjecture of Bloch on vanishing cycles, and the development of integral results keeping track of p-torsion. It is a particularly timely moment to carry out such a project as the ER has recently developed a new integral p-adic cohomology theory with Bhatt and Scholze, while the Supervisor has recently put Faltings machinery on a rigorous base in an extended joint work with Gros. The conjunction of the complementary backgrounds of the ER and Supervisor will be central to the project. Specifically, the ERs recent work with Bhatt and Scholze, as well as his expertise in K-theory, topological cyclic homology, de Rham--Witt methods, etc., will be merged with the Supervisors detailed understanding of the aforementioned works of Bloch, Kato, Tsuji, and Faltings. The theories of perfectoid spaces and pro-etale cohomology, as introduced by Scholze, will play a fundamental role.

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